Logical Channels

• Control Channels

Control channels are used for transfer of control plane information only. The control channels offered by MAC are:

• Broadcast Control Channel (BCCH)
  A downlink channel for broadcasting system control information.
• Paging Control Channel (PCCH)
  A downlink channel that transfers paging information and system information change notifications. This channel is used for paging when the network does not know the location cell of the UE.
• Common Control Channel (CCCH)
  Channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network.
• Multicast Control Channel (MCCH)
  A point-to-multipoint downlink channel used for transmitting MBMS control information from the network to the UE, for one or several MTCHs. This channel is only used by UEs that receive MBMS.
• Dedicated Control Channel (DCCH)
  A point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. Used by UEs having an RRC connection.

• Traffic Channels
  
  Traffic channels are used for the transfer of user plane information only. The traffic channels offered by MAC are:

• Dedicated Traffic Channel (DTCH)
  A Dedicated Traffic Channel (DTCH) is a point-to-point channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink.
• Multicast Traffic Channel (MTCH)
  A point-to-multipoint downlink channel for transmitting traffic data from the network to the UE. This channel is only used by UEs that receive MBMS.